A thermocouple positioning device is provided for a directional solidification casting apparatus having a furnace for receiving a mold disposed on a chill plate that, in turn, is carried on a movable ram. The thermocouple positioning device comprises a support bracket disposed on the ram for movement therewith. The bracket includes an upstanding slide member and a slideway member disposed on the slide member and having a thermocouple holder thereon. A stop member is disposed in fixed position below the furnace for releasably engaging a stop engaging member on the slideway member as the ram is raised to position the mold in the furnace. Engagement between the stop member and the stop engaging member as the ram is raised positions the thermocouple in a temperature sensing position relative to the mold in the furnace. The thermocouple remains at the temperature sensing position as the mold is withdrawn from the furnace to effect directional solidification of the melt in the mold to form a columnar or single crystal casting in the mold.